Elevating means for window shades or blinds



Dec. 10, 1963 Filed Aug. 25. l

960 2 Sheets-Sheet 1 Ffq. 1

1963 J. NISENSON ETAL 3,113,612

ELEVATING MEANS FOR WINDOW SHADES OR BLINDS Filed Aug. 25, 1960 2 Sheets-Sheet 2 including a cylindrical portion 63 having a circular end wall 65. The end wall 65 is provided with a small centrally disposed bore 66, which extends through a cylindrical member 67 forming a bearing engaging the second cylindrical portion 44 of the shaft 17. The outer surface of the cylindrical member 67 forms a toothed gear 6 8 coaxially aligned with respect to the toothed gear portion 4-3, and having one less tooth than the portion 43. The outer surface 69 of the housing 62 is preferably of a diameter to permit a force fit With respect to the inner surface 29 of the roller 15.

Referring to FIGURE 1, a stationary guide 70 is provided at the driven end of the device corresponding identically to the stationary guide 24, the same having a projecting portion 71 engageahle with the cord guide means 72. I

Movement of the cord 37 results in motion being transmitted through the pulley '36, to the spider 4'7, wherein the the gear 59 executes planetary motion about the toothed gear portion 43. As the gear 68 has one less tooth than the portion 43, a mechanical advantage equal to the number of teeth present on the gear 68 will be obtained.

Although the mechanical advantage is substantially less than that obtained by a worm drive, it is normally adequate to prevent reverse motion being transmitted back to the pulley, that is to say in which the shade or blind would unwind itself. This self locking action is not due to the degree of mechanical advantage along, but to the fact that the torque arm of the gear 68 is proportionately less than the combined torque arms of the portions 43 and 59 through which a reverse force must be transmitted, as compared with the actual mechanical advantage obtained.

We wish it to be understood that We do not consider the invention limited to the precise details of structure shown and set forth in this specification, for obvious modifications will occur to those skilled in the art to which the invention pertains.

We claim:

1. In a device for ladju-stably supporting a Window shade or blind, a generally horizontally disposed roller, bracket means supporting said roller for rotation at at least one end thereof, stationary guide means surrounding said roller at said end, said guide means including an annular surface disposed substantially perpendicular to the axis of said roller and extending radially therefrom, said guide means directly engaging said bracket means whereby said guide means is maintained substantially immobile during rotation of said roller.

2. In a device for adjustably supporting a Window shade or blind, a generally horizontally disposed roller, bracket means supporting said roller for rotation at a first end thereof, stationary guide means surrounding said roller at said end, said guide means including an annular surface disposed substantially perpendicular to the axis of said roller and extending radially therefrom, said guide means directly engaging said bracket means whereby said guide means is maintained substantially immobile during rotation of said roller; stationary cord guide means associated with said roller at a second opopsite end thereof, second stationary guide means surrounding said roller at said second end thereof, said second guide means engaging said cord guide means whereby said second guide means is maintained susbtantially immobile during transmission of motion to said roller.

References Cited in the file of this patent UNITED STATES PATENTS 168,921 Pospisil Oct. 19, 1875 1,157,261 Staats Oct. 19, 1915 1,562,192 Rowe Nov. '17, 1925 1,632,571 Watson June 14, 1927 2,217,867 McOauley Oct. 8, 1940 2,250,957 Hunter July 29, 1941 

1. IN A DEVICE FOR ADJUSTABLY SUPPORTING A WINDOW SHADE OR BLIND, A GENERALLY HORIZONTALLY DISPOSED ROLLER, BRACKET MEANS SUPPORTING SAID ROLLER FOR ROTATION AT AT LEAST ONE END THEREOF, STATIONARY GUIDE MEANS SURROUNDING SAID ROLLER AT SAID END, SAID GUIDE MEANS INCLUDING AN ANNULAR SURFACE DISPOSED SUBSTANTIALLY PERPENDICULAR TO THE AXIS OF SAID ROLLER AND EXTENDING RADIALLY THEREFROM, SAID GUIDE MEANS DIRECTLY ENGAGING SAID BRACKET MEANS WHEREBY SAID GUIDE MEANS IS MAINTAINED SUBSTANTIALLY IMMOBILE DURING ROTATION OF SAID ROLLER. 